Tension device for sewing-machines.



F. J. FRBESB. TENSION DEVICE FOR SEWING MACHINES; YAPIPLIOATIO'N rum) JUNE 4, 1901.

Patented June 18, 1912.

r- /EIZ.

tiniTnn s AiT s TaTnn'T oTTTen.

FRANCIS JOSEPH FREESE, 0F MONTREAL, QUEBEC, CANADA, ASSIGNOR TO UNITED SHOE MACHINERY COMPANY, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

TENSION DEVICE FOR SEWING-MACI-IINES.

Patented June 118, 11912 Original application filed March 31, 1897, Serial No. 630,187. Divided and this application filed June it,

- 1901. Serial No. 63,160.

To all whom it may concern Be it known that I, FRANCIS JOSEPH .Fnnnsn, of the city of Montreal, district of Montreal, and Province of Quebec, Canada,

have invented certain new and useful Im-' The object of the invention is to produce a tension device in which the tension may be applied and released at the will of the user, and to this end the invention consists in the tension device hereinafter described and particularly defined in the claims.

'In the accompanying drawings illustrating the preferred form of the invention, Figure 1 is a rear elevation of the tension device; Fig. 2 is a section on the line 22, Fig. 1, looking in the direction of the arrow; Fig. 3 is a longitudinal sectional elevation on the line 33, Fig. 3; and Fig. 4: is a transverse section on the line 4-4, Fig. 3,

looking in the direction of the arrow.

The illustrated embodiment of 'the invention is described as follows:-1 is a thread truck provided with a bushing 2, and re volving on and supported by the arbor 3. This arbor 3 is supported in a yoke attached to the framework of 'the machine. This yoke being, except as hereinafter stated, of

the usual form, is not illustrated. The two ends of the yoke which form the support. for the arbor are illustrated in the drawings, the one end being indicated by the reference (flltll'2I('.lt.l -ll and the other by the reference character 5. The arbor i5 is screw-threaded at its right-hand end and screwed into a screw-tbreaded hole in the yoke end" 4 by means of which it. is supported in proper position. The yoke end t is enlarged as shown in Fig. I} to present. a friction surface. Upon opposite sides of the thread truck 1 are provided friction washers or disks (3 and 7 of felt. The disk 0 is interposed between the right-hand side of the thread truck 1 and the surface of the yoke end i. The friction disk 7 is interposed between the lefthand surface of therthread truck 1 and the 10, by means ofwhich the pressure on the thread truck is increased or diminished. The left-hand end of the arbor 3 is screwthreaded and provided with a hand-nut 11 which may be screwed up on the arbor to in crease, or unscrewed from the arbor to decrease. the pressure on the spring 12 interposed between the ltand-nut 11 and the disk 9.. A lock-nut 13 is provided, by means of which the hand-nut 11 may be'secured in adjusted position. The hand-nut 11 is providcd'with a boss 14, which approximately fits a hole in the yoke end 5, thereby afi'ording a support for the left-hand end of the arbor 3. The friction disk 8 and the disk 9 are held from relative rotation by means of a stud 15 screw-threaded into the disk 8 and extended into a hole in the disk 9. These two disks are held-from rotation on the arbor 3 by means of the wedge 10 which is provided with an elongated slot 16 which embraces the arbor 23 and the stud 15. The wedge 10 is provided with a portion 17 of uniform thickness, and another thicker pressure-applying portion 18 of uniform thickness connected bya tapered portion 19. The disks 8 and S) are correspondingly shaped as seen in Fig. 1. \Vhen the wedge 10 is moved from the. position illustrated in Fig. 1 to the 'position illustrated in Fig. 3, the thick portion 18 of the wedge 10 is interposed be tween the thick portions of the disks 8 and t). and the pressure of the spring is thereby applied to the thread truck so as to cause it, to exert a resistance to rotation under the intluenee of the thread passing around it. When the sewing machine is in operation the "wedge will occupy the position illustrated in Fig. 3, and when it is desired to remove the work'from the machine the wedge will be raised to the position illustrated in Fig. 1, whereby the tension will be removed. The wedge is connected by a rod 20 with a treadle (not shown), a spring 21 being provided normally to lift the wedge thereby to prevent the wax onthe thread from cooling as it passes around the thread truck, a steam chest 22 is provided in the yoke end 4, a steam admission pipe admitting steam at 23, and a steam outlet pipe affording a passage away from the chest at 2 L.

The right-hand end of the arbor 3 is provided with a hole into which the steam may flow from the, steam chest By this means the yoke end 4 and the end of the arbor adjacent to the thread truck are kept hot, and by radiation and conduction, they keep the thread truck hot.

The principal feature of the invention resides in the form of the wedge, by means of which, when tension is applied, a predetermined pressure is exerted upon the thread truck, irrespective of slight variations in the position of the wedge, for so long as any portion of the thick portion 18' of the wedge is interposed between the thick portions of the disks 8 and 9, the same pressure is exerted upon the thread truck.

Having thus described the invention, what is claimed is 1. A tension device, having, in combination, a thread truck, a spring for applying resistance to the rotation thereof, and a member interposed between the truck and the spring and provided with two distinct portions of. different but each of uniform thickness; connected by a tapered portion,

said member being movable to interpose either of said portions between the truck and the spring to increase or diminish the effect of the spring on the truck, substan- I tially as described.

2. A tension device, having, in combination, a thread truck, friction washers mo'unted on opposite sides thereof, wedge members, a reciprocating wedge member located between them, said wedge members being provided with cooperating inclined faces and means for holding them from rotational movement with relatiom to each other, a

spring for pressing the thread truck, Washers and wedge members against each other, and means for reciprocating the wedge to release the action of the spring, substantially as described.

3. A tension device, having, in combination, a thread truck, a spring for applying rotational resistance thereto, and a wedge member interposed between the truck and the springprovided with a thinner portion and a thicker pressure-applying portion of; uniform thickness, said member being movsignature, in presence of two witnesses.

FRANCIS JOSEPH FREESE.

Witnesses:

WILLIAM P. MCFEAT, FRED J. SEARS. 

